open import Auto.Prelude -- using a type argument as a proof h0 : (x₁ x₂ : ⊥) → x₁ ≡ x₂ h0 = {!!} --h0 = λ x₁ → λ () -- using dependent pair to define non-dep pair module DND where _×_ : Set → Set → Set A × B = Σ A (λ _ → B) h1-2 : ∀ {A B} → A × B → B × A -- h1-2 = {!!} -- no solution found h1-2 = λ h → Σ-i {!!} {!!} -- h1-2 = λ h → Σ-i (Σ.prf h) (Σ.wit h)